Can medication be packed in the main luggage loaded in cargo hold?

Yes it can be carried. If you are talking about the legal ones, yes. (im referring to prescription medicines or OTC drugs). You just have to be mindful though of where you are going to, because certain destinations impose certain customs rules when importing medicines into their countries. Australia & USA for example, need for u to declare them on their declarations form prior to landing into their airport.. Other countries, do not mind much at all if you are carrying personal prescription medicines, such as Philippines or Morocco.